hi everyone, I have been in this forum before, my accord shift roughly on accelerating from 1 to 2 but shift smoothly from 3 to 4 auto transmission. I have change the transmission fluids no solutions yet. The D4 light is not blinking, check engine light is on. Scanning did not gives transmission problems but gives code P1491, something to do with EGR. Can this code or EGR gives rise to this problem of rough shift from 1 to 2 on accelerating. Please help. Mileage is 207,000. 4cylinders

 

I tried to upload a small snippet from shop manuals, but was defeated by file protection scheme.

It looks like hard shift for 1-2 has following possibilities to investigate:

1) Check shift solenoid valve C for siezure (not closing). An electrical fault would set a code. Make sure orings are sealing.

2) check that outlet is not clogged for 2nd clutch pressure switch.

Remaining possibilities require trans removal and teardown, which is not useful.

good luck